Improvement in metallic cartridges



f TENT QFFICE.

BENJAMIN S. ROBERTS, OF THE UNITED STATES ARMY.

IMPROVEMENT IN METALLIC CARTRIDGES.

Specification forming part of Letters Patent No. 87,297, dated February 23, 1869.

To all whom it may concern:

Be it known that I, BENJAMIN S. RoBER'rs, of the United States Army, have invented a new and useful Improvement in the Manufacture of Cartridge-Cases; and I hereby declare the following to be a full and exact description of my invention, which will be more fully understood by reference to the accompanying drawings.

The object of my invention is to form a cheap and effective cartridge-case for fixed ammunition, which shall permit of what is termed a center-tire. The difiiculty to be overcome is to furnish, in a cheap and efl'ective mode, an anvil against which the fulminate shall be sustained on the one side while it is struck by the hammer on the other.

There are various modes in which this has been done heretofore, but they have been found to be inconvenient and expensive where they have been so constructed as to prove effective. I propose a cheaper and more convenient mode of securing this object than any heretofore in use.

To enable any one skilled in the art to make and use my invention, I here furnish the requisite description.

Figure 1 shows a section of the cartridgecase when completed, such section being made through the axis of the said case. Fig. 2 is the form of a disk which is to serve as an anvil, and which is shown in section at b, Fig. 1.

This disk may be made of four arms, as shown in the drawing, or of any other number, or it may be made of other forms. That which I prefer is to take a circular disk of sheet metal and by means of proper dies to press it into a convex shape, with a cup at the bottom of the concave side to contain the fulminate, and with one or more apertures at the side of such cup to allow the fire from the fulminate to explode the powder in the cartridge. In all cases the disk, which is to serve as an anvil, should be such in its convex form as that its extreme diameter should be just sufficient to allow it to pass down into the cylindrical cartridgecase before it is tapered in the manner hereinafter shown, and its convexity should be just sufficient to cause its extreme diameter to be about equal to the interior diameter of the flange of the cartridge-case when pressed down to its seat, as is hereinafter provided for. This flange, thus strengthened, is to serve as one of the devices to be used in a combination of parts intended for retracting the cartridgeshell after the discharge'of the cartridge. By making this interior anvil of the same material as that of which the cartridge-shell is composed, galvanic action is prevented between the anvil and the shell, which might cause injury to the fulminate in the cartridge, or to the powder in the body of the shell. The drawing shows a depression or cup in the center of the base of the cartridge-shell, but this I generally omit, making the exterior surface of this base entirely flat and smooth.

In the center of this disk, in all cases, is a small depression or cup, a, which is to receive the fulminate, which is represented in Fig. 1. A smaller depression may be made in the base of the shell, which is to fall directly over the cup a, thus not only leaving between the two disks a space sufficient to contain the fulminate, but by the external depression atfording protection against an untimely discharge of the cartridge by an accidental blow upon the part containing the fulminate.

The case having been formed of the shape represented in Fig. 1, and the disk as repre sented in Fig. 2, or in any of the other shapes above contemplated, the outer ends of the arms or the outer rim of the disk are bent forward enough to diminish the diameter of the disk sufficiently to enable it to be inserted into the open end of the cartridge'case. It is then pressed down upon the base of the case, and thus flattened out, so that the arms of the disk are spread out so as to fill the full internal diameter of the flange or rim at the base of the cartridge-shell, and thus to rest upon the shoulder, forming an anvil of sufficient strength to cause the explosion of the fulminate when struck by the hammer of the look.

In pressing the disk home to the bottom of the cartridge-shell, as above contemplated, the follower (1, shown in Fig. 3, should be made hollow, or with a cup at the end sufficient to remove the cup ct,which is formed in the disk I).

The cartridge is tapered in its entire length by the tapering-machine in such a way as to close the flange solidly on the disk, holding it firmly in its position, and the taper, beginning at the base of the flange, thus made solid, supports it more strongly and securely as an anvil to resist the blow of the firing-pin and to secure certainty of fire.

I am aware that center-fire cartridge-cases have heretofore been constructed having anvils variously contrived and serving substantially the same purpose as that contemplated by me. I make no broad claim on this subject, and limit myself to the special contrivance I have presented for this purpose, or the equivalent thereof.

\Nhat I claim as my invention, and desire to secure by Letters Patent, is-

A metallic taper-shaped. center-fire cartridgeshell, holdingthe disk or anvil within its flange, secured' therein in the act of tapering the same, as herein described, and for the purposes specified.

B. S. ROBERTS,

' Brig. Gen., U. S. A. Witnesses:

JOSEPH SHELDON,

- EDWIN PURRINGTON. 

